Process of preparing a protein material



Patented on. 11, 1938 2,132,434

2,132,434 I rnocnss or rarrAnmc A raomnv MATERIAL Philip Bauer, New York, and Paul Torrington,

Jr., Forest Hills, N. Y., assignors, by mesne assignments, to Soysein Process Corporation, a corporation of New York I No Drawing. Application August 25, 1934, Serial No. 741,524

3 Claims.

This invention relates to the production of a new protein material especially suitable for use in coating andsizing of papers having properties similar to, and in some respects superior to, casein 5 derived from milk.

It is an object of this invention to derive a new protein product from vegetable matter such as commercial soya bean meal which will be inexpensive to manufacture and which will be of i superior quality.-

It is a further object to produce a protein material which may be packed and shipped dry or in the form of a paste, without deteriorating.

This protein material is preferably formed from 18 soya bean meal from which-the oil has been extracted by a solvent. It is also applicable to certain other similar meals and to meals in which the oil has not been extracted by solvents but. in general we prefer the solvent extracted meal because filtering meal. The use of sodium sulphite alone tends to more or less gum up the meal which interferes with the proper subsequent separation of the solution containing the extracted protein from the meal from which the proteins have been extracted. Sodium sulphite alone, furthermore. is not an efficient extractor of proteins but when accompanied by sodium hypochlorlte, the extraction of proteins proceeds far more efliciently. The solution containing the meal is agitated for a number of hours at amoderate temperature, for example, 60 F. and is then separated from the meal by anydesirable means, for example, by centrifuging. By reason of the nature of the solvents used the meal may be subjected to a much longer period of extraction without any danger of denaturing theoprotein, thereby making large yields possible and eliminating the need of higher temperatures. A

Apparently, there is formed an addition or sub- :0 solvent extraction is least apt to prove injurious to the protein. stitution molecule or molecules with the extracted when a, protein extraction is made 1mm v geproteins which possess the ability to resist putretable materials uch as soya, bean rapid xt faction, high adhesive strength; light color and tion at low temperature is desired, to avoid deum Solub ty.

stroying the desirable characteristics in th x- The residue meal remaining from the above 26 tracted protein. The commonly known olv ts treatment is remarkably free from the attack of that are used for this purpose u h as di putrefactivebacteria, it does not form in a hydroxide, sodium carbonate and other alkaline gummy mass and for this reason it more readily salts, are not satisfactory as they tend to deves up a ar am unt f its ava a l pr tein 30 nature the proteins and extract ert in gums d in solution and is also readily dried without cak- 30 other detrimental compounds which aifect the ing and gives a resi e m al f h g color, strength and general characteristics of the It has n p p o treat the m with a finished material. They also fail to eliminate or solution of soda sulphite in connection with lime destroy certain natural coloring matter that is to denature the product by removing certain porpresent in' thebean to the disadvantage or the t ns insoluble in lime. T s is done ther y 35 finished 'material' and also make the extracted treating the meal with a lime solution before exmaterial-and residue meal'very susceptibleto the tracting the protein or else y fi conducting attack of putrefactive bwteria. the extracting operation with the sulphite solu- The invention accordingly comprises the sevtion n t treating the 50111111011 h lime.

40 eral steps and the relation and order of one -or re y elim tin in P rtions insoluble in 40 more of suchsteps with respect to each of th lime which had previously been dissolved by the others, and the product possessing the features, sulp properties, and the relation of constituents, whi n This denaturing is in itself undesirable not only are exemplified in the following detailed disclo- On ount of its expense but also on account of sure, and the scope of the application of which the f t y p r in o certain portions 45 will be indicatedin the claims. of the protein, the final yield is reduced.

As a practical means of carrying out our proc- The denaturing of the protein interferes with ess we use soya bean meal which has been extractits desirable qualities. Where the lime treatment ed by benzene. This material is first thoroughly is first given to the protein it apparently interl ixiviated with ten times its weight of a solution feres with the subsequent sulphite reaction which 50 containing .3% (three-tens percent) sodum sulwe have found beneficial and where the lime treatphite and preferably also .l% (one-tenth perment is subsequent to the sulphite reaction the cent) sodium hypochlorite. Theuse of the hypodesirable qualities due to the sulphite are apchlorite is to give a whiter and flumer precipitate, parently destroyed.

We use the term sulphite protein" here to refer l 5 increase the yield, and assist in producing a free product;

ties of a sulphite protein and we have not foundany evidence that any sulphite addition or substitution products are formed by sulphitc in connection with lime or are present in the In some cases we have found a very satisfactory product can be obtained by. the use of sulphlte alone it the proccssfis rapidly carried out and the curd is allowed to contain a slight excess of sulphite. l

The protein solution from the above operation, after beingseparated from the meal, is precipitated by the addition of mixed hydrochloric and sulphuric acid to the pH of 4.4. After separating the. liquid from the precipitate, the precipitate is again washed with clean water adjusted.

to a pH *lfl'and after being separated from the 'wash solution enough sodium sulphite is added to this plastic mass to bring it back to a pH of 6.5. While in some cases different mixtures of acids may be used, we have found that a very desirable result can be obtained by the use of a mixture of 90% E01 and H2804 in that the protein is precipitated without other undesirable products and in a desirable physical condition. It will be understood that the proportions of acid and the relative proportions of dider'ent acids used may vary, dependent upon the par ticular batch of protein being treated.

Sulphuric acid when used alone results in certain disadvantages such as discoloration of product, a muddy precipitate, a gummy or sticky condition of the precipitate, such that it cannotbe -satisfactorily washed. On the other hand, cer

tain beneficial results flow from the use of sulphuric acid. By therefore restricting the volume of sulphuric acid and constituting the precipitating acid in large part of an acid such as hydrochloric acid, the requisite precipitation is ohtainable together with those advantages which are attributable to sulphuric acid, but under avoidance of the disadvantages which sulphuric acid alone would introduce. The particular proportions of the two acids hereinabove stated have been found to be satisfactory, but the precise limits of the percentages of the two acids where the advantageous efiects of the mixture cease to be produced vary somewhat with the precise nature of the proteins in the solution to be afiected by the acid. The important point, however, is that the sulphuric acid percentage shall be restricted to a point where disadvantageous effects which accompany its use when used alone are not set up in the product.

'lhis precipitation is preferably carried out at a temperature of about 75 F. {This precipitated protein material is granular in character and readily separates from its contained water in-a press. It is also readily filtered.

The ultimate product may be maintained in a curd form if desired, without deterioration and in that form its resolution is greatly facilitated. The material can also be dried under the influence of slight heat at-a temperature of 115 F. in an ordinary drying tunnel without discoloration.

If desired, the material may be pressed as free from water as is possible in a curd pressand may then be put in drying trays and dried under reduced pressure at 150 F. This drying is also very successfully carried out in the presence of hot acetone vapor which causes a very rapid separation of water in a short space of time and avoids any oxidation during the drying periodby the elimination of any contact with air.

This material is of very high quality. It has a color and adhesiveness' superior to that of milk casein and it is capable of going into clear solution. It will readily dissolve in any one of a large number of solvents, but we have found that borax or ammonia both produce suitable results.

Since certain changes in carrying out the above process and certain modifications in the composition which emb'ody the invention may be made without departing from its scope, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

Itis also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and allstatements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What we claim and desire to'secure by Letters Patent is:

=1; The process of forming a vegetable pro- ,tein material which comprises dissolving protein from a vegetable mealpseparating the protein-containing solution, precipitating the protein by acid treatment, separating the precipitate from the supernatant liquid, eliminating protein material soluble in the acid precipitate: solution, bringing the precipitate to a condition of a plastic mass and adding an alkali metal sulphite, and then reducing the paste to dry powdered form under preservation in the powder of the added sulphi'te.

2. The process of forming a vegetable protein material which comprises dissolving protein from a vegetable meal, separating the protein-com taining solution, precipitating the protein by acid treatment, separating the precipitate from the supernatant liquid, eliminating protein material soluble in the acid precipitator solution, bringing the precipitate to a condition of a plastic mass, and adding an alkali metal sulphite and preserving the plastic condition in the mass whereby the product can be directly shipped as a paste containing sulphite and be used in the paper-coating industry in paste form. 

